Although the human anatomy provides in man the innate, or natural, ability to see in depth, or stereopsis, the three-dimensional real world scene, where the visual "screen" for the eyes is of infinite depth, man does not have such natural ability when the viewing screen is two-dimensional, as in the video arts, e.g., the motion picture and television fields. For years attempts have been made to reproduce three-dimensional, real world scenes so that they can be viewed in depth on a two-dimensional surface.
The anatomical and psychological capability of men to visualize the three-dimensional, live world scene in stereopsis, or depth, has long been a subject of investigation, and much has been learned and written about the human visual apparatus, i.e., the eyes and brain of the body. It is generally known that man's natural ability to visualize three-dimensional objects and scenes in depth, or stereopsis, is due to a combined operation of the two eyes and the brain to produce a visio-psychological impression in the mind. More specifically, it is known that the actual view received in the left eye and the actual view received in the right eye, when a visual scene is observed, are slightly different because of the displacement, or distance of separation, of the eyes in the head. This interocular separation, or disparity, is approximately 63 mm, or 21/2 inches, in the normal adult. These slightly differing right and left views received by the respective eyes are continuously transmitted to the brain where the right and left views are psychologically "combined" by the brain to create a resultant "cyclopean", or one-eye, view in the mind, wherein near objects and far objects in the three-dimensional real world scene appear at their actual distances from the observer. Most authors believe that a true fusion of right and left eye views occurs in the brain to produce the single "cyclopean" view of the mind, although there is another theory that a "replacement" phenomena occurs wherein the brain alternately suppresses right and left eye views to produce the cyclopean resultant view in the mind. In any event it is agreed that the ability of man to visualize a three-dimensional scene in depth is principally attributed to the visual parallax created by the interocular separation of the eyes to provide the brain with slightly different left and right views of the same scene. This is supported by the fact that a one-eyed man cannot observe three-dimensional scenes in depth as does the two-eyed individual.
It has also been postulated that in the human visual apparatus the single eye sees both right and left views of a visual scene, i.e., the right view being that which is "seen" by the right eye temporal retina and the left eye nasal retina, and the left view being that which is "seen" by the right eye nasal retina and the left eye temporal retina. However, three-dimensional effect is suppressed or not obtained with the single eye in fixed position because of lack of disparity, i.e., distance of separation, of the two single eye views.
Therefore, in attempts to reproduce three-dimensional scenes in depth on a two-dimensional surface, many have been led to take left and right view photographs with cameras spaced at ocular separation, i.e., as the human eyes would actually see the same scene, to superimpose these photographs on a two-dimensional screen, and in viewing the scene, to block all right views for the left eye and left views from the right eye of the observer to permit three-dimensional assimilation of the views by the brain.
Early work in the area of three-dimensional still photography produced the steroptican, in which two single frame pictures recorded on film by a stereocamera having a lens base separation equal to the distance between the human eyes are simultaneously projected from spaced projection points and superimposed upon a screen to produce a composite picture which can be observed in depth. In the motion picture field, motion pictures have been produced for viewing in depth by use of multiple projectors and filmstrips which simultaneously project, with differently polarized light, right and left images of a visual scene onto a screen. By wearing correspondingly polarized glasses, a viewer receives only left view images in the left eye and right view images in the right eye so that the visio-psychological operation of the human visual apparatus produces an impression of stereopsis in the mind of the viewer. Although such three-dimensional motion pictures were commercially exhibited to the public, they apparently were not well accepted, and their popularity was short-lived in the industry. Such motion pictures not only required the purchase and use of special additional projection equipment and glasses which had to be worn by the viewers, but also the stereopsis, or depth, produced in the pictures was overly exaggerated and appeared to be more than that seen in real life, quite often causing many viewers to experience headaches as a result of viewing the pictures.
It has also been proposed in the past to provide apparatus and processes for recording and reproducing visual scenes for viewing in stereopsis by the unaided eye, i.e., without the necessity of special glasses or viewing equipment to be used by the viewing audience. Typical apparatus and processes heretofore proposed for three-dimensional photography are described in the following U.S. patents:
______________________________________ 765,980 Mercier 2,627,200 Huber 1,307,074 Baruch 2,838,975 Laube 1,939,343 Feil 2,891,440 Barake 2,080,604 Draper 2,952,182 Marks et al 2,101,979 Brock 3,006,241 Marks et al 2,114,060 Oakley 3,240,549 Wells 2,157,099 Rosenhauer 3,482,908 McCormick 2,194,737 Cathey 3,482,913 Glenn, Jr. 2,566,700 Goldsmith ______________________________________
U.S. Pat. Nos. 2,101,979 and 2,157,099 propose the production of stereoptic motion pictures by photographing left and right views of a scene from laterally spaced positions less than interocular with a single camera having rotating mirror and blocking shutter, respectively, to record the views on alternate single frames of a moving filmstrip. U.S. Pat. No. 2,101,979 further suggests that the frames of the filmstrip may be laterally shifted to align the same on the strip and reduced disparity between left and right views.
U.S. Pat. No. 3,366,438 discloses the use of multiple cameras with mirrors and lens system to photograph a scene from laterally spaced positions for stereoptic reproduction.
Although numerous proposed solutions, as indicated in the foregoing patents, have been given to enable production of motion pictures for visualization in three-dimension by the unaided eye, I know of no present commercially accepted or used process or system which proves the validity of the aforementioned proposals or achieves this long sought objective. In addition, many prior art proposals require highly specialized, complicated equipment for projection and viewing which requires extensive and expensive modification of existing equipment in the video arts.